Throughout his work, Adorno contrasted liberal ideology to the newer and more pernicious form of ideology found in positivism. The paper explores the philosophical basis for Adorno's contrast between liberal and positivist ideology. In Negative Dialectics, Adorno describes all ideology as identity-thinking. However, on his view, liberal ideology represents a more rational form of identity-thinking. Fearing that positivism might obliterate our capacity to distinguish between what is and what ought to be, Adorno sought a more secure foundation for his critique of existing conditions. He found this basis in liberal discourse. In the concept of freedom, for example, Adorno located ideas or ideals that negate and transcend the given. One of the conditions for the possibility of critical thought lies in such ideas; critical thinking consists in wielding the more emphatic content of concepts against the pathic rationality of existing conditions. Far from prescribing mimesis as the antidote to a damaged social, political and economic reality, then, Adorno advocates a more dialectically inflected use of concepts as the basis for social criticism. Key Words: Adorno  Critique  Identity  Ideology  Liberalism  Positivism.